Gas Electron Multiplier (GEM) based coordinate detectors are used at different high energy physics centres and at Budker Institute of Nuclear Physics particularly. These detectors possess a spatial ...resolution in ten micron scale together with high rate capability up to 107 cm−2s−1. Thus, the precise investigation of best possible spatial resolution, achieved with GEM-detectors, is the subject of interest. The experimental data, accumulated by the moment, gives the possibility to compare it with the simulation results. The simulation of applied detector configurations includes transport of electrons through the detector and tracking of avalanche evolution inside the working volume, as well as obtaining signal distribution on the readout strips. The spatial resolution, obtained in the simulation of an individual detector, is found to be essentially better (the difference is about two standard deviations) than the experimental results. Further efforts to find out the reasons of the contradiction between the simulation and measurements were made. In particular, the simulation of complete experimental set-up (including tracking detectors) was performed. The results of individual detector simulation and the simulation of complete set-up were determined to generally coincide.
Spatial resolution of triple-GEM detectors Kudryavtsev, V.N.; Maltsev, T.V.; Shekhtman, L.I.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Volume:
936
Journal Article
Peer reviewed
Gas Electron Multiplier (GEM) based detectors are widely used in numerous collider experiments and, in particular, at the Budker Institute of Nuclear Physics (BINP). In order to determine the best ...possible spatial resolution, the simulation of charged particle registration process is accomplished. The simulation shows that spatial resolution is definitely less than 20μm for applied operation configurations. The simulation of electron transport through single GEM and through GEM-cascade shows that an electron cluster is compressed by GEM holes and an effective transverse diffusion is reduced by approximately 15% as maximum. The experimental part of the work is devoted to the operability tests of the designed detector with orthogonal strips readout with a pitch of 250μm and the measurements of its characteristics including the dependence of gain on GEM-voltage, the registration efficiency and the spatial resolution. Spatial resolution of the studied detector is measured as 31.5±0.9(stat.)−7.5+6.9(syst.)μm.
This paper describes systematic measurements of the main parameters of the DIMEX-Si silicon microstrip detector prototype, designed to study fast processes in a beam of synchrotron radiation (SR). ...The dynamic range, spatial resolution and temporal parameters of the detector are estimated. The parameters of the prototype silicon detector are compared with the DIMEX-G gas version. The maximum flux which can be measured by the silicon detector is 40 times higher than that of the gas detector. The spatial resolution of the silicon detector is 130 microns and that of the gas detector is 250 microns. The estimated time resolution of the silicon detector is 15 ns, while for a gas detector this value is about 50 ns. All the characteristics of DIMEX-Si are measured with a cycle time of 25 ns. The results of the first tests of a full-scale silicon detector for diffraction studies, operating in the integrating mode at a speed of up to 2 Mframes/s, are also given. The sensor contains 1024 strips 30 mm long with a step of 50 microns; 512 of these strips are connected to readout electronics based on APC128 ASIC. Each chip contains 128 channels, which consist of a low-noise integrator with 32 analog memory cells. The possibility of signal visualization from single photons and electrons from
109
Cd and
90
Sr sources is shown.
The work describes a one-dimensional detector for diffraction experiments at a synchrotron radiation beam. The detector is being developed at the Budker Institute of Nuclear Physics, Siberian Branch, ...Russian Academy of Sciences. Until recently the institute was developing gas one-coordinate detectors, in particular a one-coordinate detector with calculated channels (OD-3M), based on the technology of multiwire proportional chambers. To provide a spatial resolution better than 100 microns at a photon energy in a wide energy range (3–30 keV), it is necessary to use solid-state microstrip or matrix sensors in combination with specialized integrated registration circuits. The developed SOCOD detector, using a microstrip sensor based on gallium arsenide as a registration element, operates in the mode of the direct counting of photons with an energy of more than 3–4 keV and a speed of up to 1 MHz/channel. The work gives a general description of the current version of the detector, a block diagram of the registration channel, the software allowing users to control the operation of the detector and display the results obtained, and the developed algorithm for leveling the trigger thresholds in the channels. The results of electronic tests, the work of the alignment algorithm and their discussion are presented.
In this work we present experimental data on measuring distributions of small- angle X-ray scattering (SAXS) during cast trinitrotoluene (TNT) detonation of 30 and 40 mm in diameter. Dynamics of ...average size of condensed carbon nanoparticle inkreases has been restored from experimental SAXS data. The work was carried out at the SYRAFEEMA (Synchrotron Radiation Facility for Exploring Energetic Materials) station at accelerator complex VEPP- 4M (Budker Institute of Nuclear Physics). We observe minimal size of particles of order of 2 nm directly behind the detonation front. Later, the average size of carbon nanoparticles increases within 4-12 μs and reach values of 6 nm.
The spatial resolution of GEM based tracking detectors has been simulated and measured. The simulation includes the GEANT4 based transport of high energy electrons with careful accounting for atomic ...relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing, including accounting for diffusion, gas amplification fluctuations, the distribution of signals on readout electrodes, electronics noise and a particular algorithm of the final coordinate calculation (center of gravity). The simulation demonstrates that a minimum of the spatial resolution of about 10
μ
m can be achieved with strip pitches from 250
μ
m to 300
μ
m. For larger pitches the resolution is quickly degrading reaching 80-100
μ
m at a pitch of 500
μ
m. The spatial resolution of low-material triple-GEM detectors for the DEUTRON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4M collider. The amount of material in these detectors is reduced by etching the copper of the GEMs electrodes and using a readout structure on a thin kapton foil rather than on a glass fibre plate. The exact amount of material in one DEUTRON detector is measured by studying multiple scattering of 100 MeV electrons in it. The result of these measurements is X/X0 = 2.4×10
−3
corresponding to a thickness of the copper layers of the GEM foils of 3
μ
m. The spatial resolution of one DEUTRON detector is measured with 500 MeV electrons and the measured value is equal to 35 ± 1
μ
m for orthogonal tracks.
In this paper, we describe the current state of development of a prototype detector for the study of fast processes (DIMEX) based on a silicon microstrip sensor. The silicon microstrip sensor is made ...of
n
-type silicon with
p
-type implants in the form of strips. Aluminum contacts with microwelding pads at the ends are applied to the strips along the entire length. The signals from the strips are read using a DMXS6A integrated circuit specially designed for this project, which contains six recording electronic channels with a dark-current compensation circuit at the input, four integrators, 32 analog memory cells, and an analog shift register. Each sensor strip is connected to the guard ring through a 400-Ω resistor and to the recording-channel input through a 100-kΩ resistor. This resistive divider at the input of the recording channel makes it possible to adapt the dynamic range of the recording microcircuit integrator to the full range of photon-flux changes in synchrotron-radiation output channel no. 8 of the VEPP-4M storage ring equipped with a nine-pole wiggler with a field of 1.95 T as the source of synchrotron radiation. Measurements of the dynamic range of the DIMEX-Si prototype show that the maximal flux that can be recorded in the linear mode exceeds 10
5
photons/channel from each electron bunch in the storage ring. The ability of the detector to detect signals from bunches following after 55 ns in the multi-bunch mode, which simulates the operation of the 4+-generation synchrotron-radiation source Siberian Circular Photon Source (SKIF) under construction in the Novosibirsk region, on which such a detector is planned to be used, is also demonstrated.
Time resolved small angle x-ray scattering (SAXS) experiments on detonating high explosives have been conducted at the Lavrentyev Institute of Hydrodynamics and the Budker Institute of Nuclear ...Physics. The purpose of these experiments is to measure the SAXS patterns behind the detonation front and restore the dynamics of a carbon condensation process. The deficiency of the experimental data hinders the development of detonation models. In this work we present a new method to restore the dynamic of carbon condensation from time resolved SAXS patterns.
The optical scheme of a synchrotron beamline for measuring small-angle X-ray scattering curves with high temporal resolution is developed as a part of constructing the 1–3 Fast Processes beamline of ...the SKIF 4+ generation synchrotron radiation facility. Such measurements are badly needed nowadays to study the dynamic processes that occur with carbon particles when high-energy materials explode and other technological problems.
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